Associations between TLR9 polymorphisms and cancer risk: evidence from an updated meta-analysis of 25,685 subjects

TLR8 and TLR9 gene polymorphisms and the risk of high-grade serous ovarian cancer

High-grade serous ovarian carcinoma (HGSOC) is the most prevalent and lethal histotype of epithelial ovarian cancer (EOC). Single nucleotide polymorphisms (SNPs) in Toll-like receptor (TLR) genes may serve as important markers of susceptibility to numerous cancers. We explored the frequency of TLR8 and TLR9 polymorphisms in 325 women and determined their role in susceptibility to EOC and viral infection. The group of patients with EOC included 93 HGSOC and 32 non-HGSOC cases. TLR8 rs3764879, TLR8 rs3764880, TLR9 rs352139, and rs352140 SNPs were genotyped using the allelic discrimination method. The homozygous recessive genotypes for TLR8 rs3764879 and TLR9 rs352139 SNPs were more common in patients with EOC, compared to healthy women, and increased the risk of ovarian cancer (p = 0.0001 and p < 0.05, respectively). The TLR8 rs3764879 SNP reached statistical significance after Bonferroni's correction for multiple tests. The homozygous recessive genotype for TLR8 rs3764879 (-129C>G) was associated with a five-fold increased risk of HGSOC (p = 0.0001). A mutation in at least one allele of the TLR8 rs3764879 was also associated with a higher level of TLR8 expression in tumor tissues (p = 0.0008). The present study demonstrated a strong association between the TLR8 -129C>G SNP and an increased risk of the HGSOC subtype.

Association between TLR 2 (rs3804099), TLR4 (rs4986790), and TLR 9 (rs187084) polymorphism and leukemia risk: a systematic review and meta-analysis

Toll-like receptors (TLRs) are crucial components of innate immunity. A specific form of genetic variation in TLR genes may increase the chance of developing leukemia. The present investigation conducted a comprehensive meta-analysis to examine the correlation between three TLR polymorphisms, namely TLR2 (rs3804099), TLR4 (rs4986790), and TLR9 (rs187084), within the leukemia risk group. An in-depth literature search was performed using Web of Science, PubMed, and Google Scholar to identify noteworthy research published in these scientific databases from 2012 to 2024. Research articles were evaluated according to rigorous inclusion criteria, and data was compiled for meta-analysis using Microsoft Excel (Ver. 2013), MedCalc (Ver. 19.3), and RevMan software (Ver. 5.3). Finally, 11 qualified studies were selected for the ongoing investigation, encompassing a combined total of 1315 leukemia cases and 1340 controls. Using a dominant genotype model, the meta-analysis found that the TLR2 (rs3804099) and TLR9 (rs187084) polymorphisms were strongly linked to higher risk of leukemia, with ORs of 2.042 (95% CI: 1.35-3.08, p = 0.001) and 1.38 (95% CI: 1.14-1.67, p = 0.001) respectively. Notably, the TLR4 (rs4986790) polymorphism did not exhibited any substantial correlation with the incidence of leukemia. The results indicate that variations in TLR2 and TLR9 genes could be considered a novel genetic biomarker for the leukemia development, highlighting their potential use in risk assessment and targeted therapies. This emphasizes the possibility of using these variations in evaluating risk and developing targeted remedies. However, greater research capacities are required to research into the fundamental mechanisms and authenticate these trends in other populations.

Revealing of TLR-9 gene polymorphisms by qPCR HRM technique and their influence on TLR-9 serum level in acute myeloid leukemia patients: Case-control study

Acute myeloid leukemia (AML) is one of the most common and fatal malignancies that affect adults, which can quickly become aggressive if left untreated, and leukemia cells invade the bone marrow. TLR-9 is an innate immune cell receptor sensitive to various PAMPs and encoded by the TLR-9 gene. As is often known, genetic polymorphisms in any gene can help the development of the disease, and these three polymorphisms, rs187084, rs5743836, and rs352140 of TLR-9, have been studied in many different cancer disorders. Therefore, this study aimed to discover the multiple forms of a TLR-9 gene in a sample of Iraqi AML patients. A total of 120 participants in a case-control study were enrolled in the current study. Using CBC, some hematological parameters were evaluated, and the serum level of TLR-9 was assessed using the ELISA technique. DNA was extracted directly from blood, and a high-resolution melting (HRM) analysis was then carried out. The results revealed a significant difference in some blood parameters among patients and healthy control, while WBC and lymphocytes were without an evident difference between the two groups of the current investigation. The serum concentration of TLR-9 showed an elevated level in patients (P value < 0.01). Nonetheless, this increase was not affected by the genotype patterns of polymorphisms. According to the P-value, there was a significant difference in wild genotypes of the three polymorphisms (rs187084, rs5743836, and rs352140). At the same time, the odds ratio revealed the association with the disease as a protective factor. In contrast, there was a significant difference in the heterozygous and mutant genotypes of TLR-9 polymorphisms, though the odds ratio confirmed the association with the AML as a risk factor. The results of rs352140 were compatible with H.W.E since there were no significant differences between the observed and expected values for either patients or healthy controls. In contrast, the result of rs5743836 was not consistent with the HWE. Furthermore, although it corresponds with the healthy one, the finding of rs187084 conflicted with H.W.E. in the patient group. In conclusion, High serum levels of TLR-9 in patients could act as biomarkers for AML. The TLR-9 gene polymorphisms (rs187084, rs5743836, and rs352140) have been linked to an increased risk of AML and may impact the disease progression in the Iraqi population.

Innate Immune Program in Formation of Tumor-Initiating Cells from Cells-of-Origin of Breast, Prostate, and Ovarian Cancers

Tumor-initiating cells (TICs), also known as cancer stem cells (CSCs), are cancer cells that can initiate a tumor, possess self-renewal capacity, and can contribute to tumor heterogeneity. TICs/CSCs are developed from their cells-of-origin. In breast, prostate, and ovarian cancers, progenitor cells for mammary alveolar cells, prostate luminal (secretory) cells, and fallopian tube secretory cells are the preferred cellular origins for their corresponding cancer types. These luminal progenitors (LPs) express common innate immune program (e.g., Toll-like receptor (TLR) signaling)-related genes. Microbes such as bacteria are now found in breast, prostate, and fallopian tube tissues and their corresponding cancer types, raising the possibility that their LPs may sense the presence of microbes and trigger their innate immune/TLR pathways, leading to an inflammatory microenvironment. Crosstalk between immune cells (e.g., macrophages) and affected epithelial cells (e.g., LPs) may eventually contribute to formation of TICs/CSCs from their corresponding LPs, in part via STAT3 and/or NFκB pathways. As such, TICs/CSCs can inherit expression of innate-immunity/TLR-pathway-related genes from their cells-of-origin; the innate immune program may also represent their unique vulnerability, which can be explored therapeutically (e.g., by enhancing immunotherapy via augmenting TLR signaling).

Association of TLR4 Rs4986791 Polymorphism and TLR9 Haplotypes with Acute Myeloid Leukemia Susceptibility: A Case-Control Study of Adult Patients

Toll-like receptors (TLRs) have an important role in innate immunity, and single nucleotide polymorphisms (SNPs) of TLR genes influence the risk of developing hematological malignancies. We aimed to evaluate the effect of TLR2 (rs5743708), TLR4 (rs11536889, rs4986790, rs4986791), TLR9 (rs187084, rs352140, rs5743836) on AML risk, the relation between investigated SNPs and somatic mutations, clinical features, and the overall survival of adult AML patients. All mentioned SNPs were genotyped in 511 AML cases and 503 healthy controls. DNMT3A (R882), FLT3 (D835, ITD), and NPM1 mutations' status were investigated in AML patients. TLR4 rs4986791 was associated with an increased risk of AML under the dominant model (OR = 1.61, 95% CI: 1.001-2.59). Variant genotypes of the TLR4 rs4986790 or rs4986791 were associated with the odds of developing AML in the codominant model (OR = 3.14; 95% CI: 1.12-8.84; p = 0.032). The TLR9 rs5743836 variant genotype was associated with the NPM1 mutation (p = 0.002). The investigated SNPs were not associated with the DNMT3A, FLT3 mutations and had no significant contribution to the hazard of death after adjusting for covariates. Our findings suggest that TLR4 rs4986791 is associated with AML susceptibility. The combined variant genotypes of TLR4 rs4986790 and rs4986791 increase AML risk, the TLR9 C-G-A haplotype may represent a promising approach to predict a person's risk for developing AML.

Polymorphisms and haplotypes of TLR4, TLR9 and CYP1A1 genes possibly interfere with high-risk human papillomavirus infection and cervical cancer susceptibility in Jharkhand, India

BACKGROUND

Expression and single nucleotide polymorphisms (SNPs) of TLR4/9 and CYP1A1 genes are vital for cervical squamous cell carcinoma (CSCC) but considerably vary in different populations.

METHODS

A total of 255-subjects from Jharkhand (130-cases, 125-controls) were utilized to obtain the expression/SNP status of TLR4/9, CYP1A1, and E6 (HPV16/18) by RT-PCR, WB, and allele-specific-PCR followed by sequencing.

RESULTS

Over-expression of TLR4/9 and high infection of HPV16/18(78.5%) were found to be associated with CSCC. Among the seven SNPs(p1-p7) tested, the CT-genotype (p3:rs1927911; OR = 2.142; p = 0.004) and 'T'-allele (p3; OR = 1.694; p = 0.0061) of TLR4; CC-genotype (p4:rs5743836; OR = 3.307; p = 0.0018), 'C'-allele (p4; OR = 1.895; p = 0.0009), GA-genotype (p5:rs352140; OR = 2.064; p = 0.0172), AA-genotype (p5; OR = 2.602; p = 0.0021) and 'A'-allele (p5; OR = 1.939; p = 0.0002) of TLR9; and the TC-genotype (p6:rs4646903; OR = 1.967; p = 0.0452) and GG-genotype (p7:rs1048943; OR = 2.336; p = 0.0287) and 'G'-allele (p7; OR = 1.685; p = 0.0082) of CYP1A1 were associated with an increased-risk of CSCC. Similarly, the p3:CT-genotype (OR = 1.993; p = 0.0134); p4:CC-genotype (OR = 3.071; p = 0.0057) and 'C'-allele (OR = 1.838; p = 0.0029); p5:AA-genotype (OR = 2.231; p = 0.0147) and 'A'-allele (OR = 1.756; p = 0.0032); p6:TC-genotype (OR = 2.370; p = 0.02); and the p7:GG-genotype (OR = 2.255; p = 0.0488) and 'G'-allele (OR = 1.691; p = 0.0118) showed an association with HPV16/18 infection. Conversely, TLR4 (p1-p2-p3:A-G-T; OR = 3.361; p = 0.029), TLR9 (p4-p5:C-A; OR = 1.786; p = 0.032) and CYP1A1 (p6-p7:C-G; OR = 1.783; p = 0.033) haplotypes with CSCC susceptibility was observed, whereas the TLR4 (p1-p2-p3:A-C-C; OR = 0.4675; p = 8.E-3) and TLR9 (p4-p5:T-G; OR = 0.3937; p = 0.00) haplotypes showed protection against the development of CSCC. Further, though p1:rs10759931 and p2:rs11536889 were found to be insignificant, the p3:CT-genotype, p5:GA/AA-genotype, and p7:GG-genotype were associated with elevated protein; the p4:CC-genotype and p6:TC-genotype were associated with increased mRNA compared to their respective-wild-type-groups.

CONCLUSION

The present study revealed an association between TLR4/9 and CYP1A1 polymorphisms with increased HPV16/18 infection susceptibility and CSCC risk among the women of Jharkhand state.

Toll-like receptor 9 polymorphisms and Helicobacter pylori influence gene expression and risk of gastric carcinogenesis in the Brazilian population

BACKGROUND

Toll-like receptors (TLRs) are the first line of host defense, and are involved in Helicobacter pylori (H. pylori) recognition and activation of both inflammatory and carcinogenic processes. The presence of single nucleotide polymorphisms (SNPs) in genes that activate the immune response may modulate the risk of precancerous lesions and gastric cancer (GC). Among them, Toll-like receptor 9 (TLR9) polymorphisms have emerged with a risk factor of infectious diseases and cancer, however the studies are still inconclusive.

AIM

To evaluate whether TLR9 rs5743836 and rs187084 SNPs contribute to the risk of gastric carcinogenesis, and its influence on mRNA expression.

METHODS

A case-control study was conducted to evaluate two TLR9 SNPs (TLR9-1237 TC-rs5743836 and TLR9-1486 CT-rs187084) in chronic gastritis (CG) and GC patients. A total of 609 DNA samples of peripheral blood [248 CG, 161 GC, and 200 samples from healthy individuals (C)] were genotyped by polymerase chain reaction-restriction fragment length polymorphism. All samples were tested for the H. pylori infection using Hpx1 and Hpx2 primers. Quantitative polymerase chain reaction by TaqMan^® assay was used to quantify TLR9 mRNA from fresh gastric tissues (48 GC, 26 CG, and 14 C).

RESULTS

For TLR9-1237, the TC + CC or CC genotypes were associated with a higher risk of GC than C [recessive model odds ratio (OR) = 5.01, 95% confidence interval (CI): 2.52-9.94, P < 0.0001], and the CG (recessive model OR =4.63; 95%CI: 2.44-8.79, P < 0.0001) groups. For TLR9-1486, an association between the CT + TT genotypes and increased risk of both GC (dominant model OR = 2.72, 95%CI: 1.57-4.72, P < 0.0001) and CG (dominant model OR = 1.79, 95%CI: 1.15-2.79, P = 0.0094) was observed when compared to the C group. Moreover, the presence of TLR9-1237 TC/CC + TLR9-1486 CC genotypes potentiate the risk for this neoplasm (OR = 18.57; 95%CI: 5.06-68.15, P < 0.0001). The TLR9 mRNA level was significantly higher in the GC group (RQ = 9.24, P < 0.0001) in relation to the CG group (RQ = 1.55, P = 0.0010) and normal mucosa (RQ = 1.0). When the samples were grouped according to the polymorphic genotypes and the presence of H. pylori infection, an influence of TLR9-1237 TC + CC polymorphic genotypes (P = 0.0083) and H. pylori infection (P < 0.0001) was observed on the upregulation of mRNA expression.

CONCLUSION

Our findings show that TLR9 rs5743836 and rs187084 polymorphisms are associated with a higher risk of carcinogenesis gastric, and that TLR9 mRNA levels can be modulated by TLR9-1237 TC + CC variant genotypes and H. pylori infection.

TLR9-1486C/T polymorphism is associated with hepatocellular carcinoma recurrence after liver transplantation

Aim: To determine whether TLR9 polymorphisms are associated with tumor recurrence after liver transplantation for hepatocellular carcinoma (HCC). Patients & methods: All patients who underwent liver transplantation, and had viable HCC in the explanted liver were included. TLR9-1237C/T and -1486C/T polymorphisms were analyzed by real-time PCR and melting curves analysis. Results: 20 of 159 patients (12.6%) developed post-transplant HCC recurrence. Tumors exceeding Milan criteria, moderately-to-poorly differentiated tumors and microvascular invasion on explants, and pretransplant α-fetoprotein level (all p < 0.01) were associated with an increased risk, while TLR9-1486TT genotype was associated with a decreased risk of HCC recurrence (p = 0.03). Conclusion: TLR9-1486C/T might help to preoperatively identify patients at low risk of post-transplant HCC recurrence.

Evaluation of the Relationship Between Common Variants in the TLR-9 Gene and Hip Osteoarthritis Susceptibility

Objective: Hip osteoarthritis (HOA) is one of the most common types of osteoarthritis and affects nearly 10% of men and 18% of women who are >60 years of age worldwide. It has been demonstrated to be a genetic disease with a 50% heritability risk. Recently, the TLR-9 gene has been associated with knee OA in both Turkish and Chinese populations, but the relationship between the TLR-9 gene and HOA has not been evaluated. In this study, we aimed to evaluate the relationship between the common genetic variants in the TLR-9 gene and the predisposition of Han Chinese individuals to HOA. Methods: A total of 730 HOA patients and 1220 healthy controls were recruited in a hospital-based case-control study. Six common single nucleotide polymorphisms (SNPs) of the TLR-9 gene were selected for genotyping, and genetic association analyses were performed using both single-marker and haplotype-based methods. Results: The SNP rs187084 was found to be significantly associated with the risk of HOA after a Bonferroni correction (adjusted allelic p-values with age, gender, and body mass index [BMI] = 0.0008). The results indicated that the A allele of rs187084 is a risk allele for HOA and is likely to be a predisposing factor leading to an increased risk of HOA (adjusted odds ratio with age, gender, and BMI = 1.26, 95% confidence interval = 1.10-1.43). The results of the haplotype analyses confirmed a similar pattern to the SNP analyses. Conclusions: Our study provides strong evidence that variations in the TLR-9 gene are closely linked with genetic susceptibility to HOA in the Han Chinese population. This finding furthers the role of TLR-9 in the development and occurrence of OA in general.

Beyond PD-1/PD-L1 Inhibition: What the Future Holds for Breast Cancer Immunotherapy

Cancer immunotherapy has altered the management of human malignancies, improving outcomes in an expanding list of diseases. Breast cancer - presumably due to its perceived low immunogenicity - is a late addition to this list. Furthermore, most of the focus has been on the triple negative subtype because of its higher tumor mutational load and lymphocyte-enriched stroma, although emerging data show promise on the other breast cancer subtypes as well. To this point the clinical use of immunotherapy is limited to the inhibition of two immune checkpoints, Programmed Cell Death Protein 1 (PD-1) and Cytotoxic T-lymphocyte-associated Protein 4 (CTLA-4). Consistent with the complexity of the regulation of the tumor - host interactions and their lack of reliance on a single regulatory pathway, combinatory approaches have shown improved efficacy albeit at the cost of increased toxicity. Beyond those two checkpoints though, a large number of co-stimulatory or co-inhibitory molecules play major roles on tumor evasion from immunosurveillance. These molecules likely represent future targets of immunotherapy provided that the promise shown in early data is translated into improved patient survival in randomized trials. The biological role, prognostic and predictive implications regarding breast cancer and early clinical efforts on exploiting these immune-related therapeutic targets are herein reviewed.

The Associations between Toll-Like Receptor 9 Gene Polymorphisms and Cervical Cancer Susceptibility

This meta-analysis systematically reviews the association between Toll-like receptor 9 polymorphisms and the risk of cervical cancer. Case-control studies focused on the association were collected from the PubMed, Web of Science, Cochrane Library, Embase, MEDLINE, CNKI, VIP, and Wanfang databases from inception to July 2017. We screened the studies and assessed the methodological quality of the included studies and extracted data. A meta-analysis was performed using RevMan 5.3 and Stata 12.0 software. Pooled odds ratios and 95% confidence intervals were employed to evaluate the strength of the associations between Toll-like receptor 9 polymorphisms and cervical cancer risk. A total of 9 studies comprising 3331 cervical cancer patients and 4109 healthy controls met the inclusion criteria. Of these, 8 studies contained information about G2848A (rs352140) and 4 studies contained information about −1486T/C (rs187084). Our results revealed that the associations between rs187084 and cervical cancer risk in the dominant model (p = 0.002) and heterozygous model (p = 0.002) were significant, with 1.30- and 1.32-fold increases in susceptibility, respectively, compared to that in the wild-type model. However, rs352140 was not related to cervical cancer regardless of whether the subgroup analysis was conducted (p > 0.05). In conclusion, there is a significant correlation between rs187084 and cervical cancer risk with the minor C allele increasing the risk of occurrence of cervical cancer. However, rs352140 is not associated with the occurrence of cervical cancer.

Lower frequency of TLR9 variant associated with protection from breast cancer among African Americans

Introduction

Toll-like receptor 9 (TLR9) is an innate immune system DNA-receptor that regulates tumor invasion and immunity in vitro. Low tumor TLR9 expression has been associated with poor survival in Caucasian patients with triple negative breast cancer (TNBC). African American (AA) patients with TNBC have worse prognosis than Caucasians but whether this is due to differences in tumor biology remains controversial. We studied the prognostic significance of tumor Toll like receptor-9 (TLR9) protein expression among African American (AA) triple negative breast cancer (TNBC) patients. Germline TLR9 variants in European Americans (EAs) and AAs were investigated, to determine their contribution to AA breast cancer risk.

Methods

TLR9 expression was studied with immunohistochemistry in archival tumors. Exome Variant Server and The Cancer Genome Atlas were used to determine the genetic variation in the general EA and AA populations, and AA breast cancer cases. Minor allele frequencies (MAFs) were compared between EAs (n = 4300), AAs (n = 2203), and/or AA breast cancer cases (n = 131).

Results

Thirty-two TLR9 variants had a statistically significant MAF difference between general EAs and AAs. Twenty-one of them affect a CpG site. Rs352140, a variant previously associated with protection from breast cancer, is more common in EAs than AAs (p = 2.20E-16). EAs had more synonymous alleles, while AAs had more rare coding alleles. Similar analyses comparing AA breast cancer cases with AA controls did not reveal any variant class differences; however, three previously unreported TLR9 variants were associated with late onset breast cancer. Although not statistically significant, rs352140 was observed less frequently in AA cases compared to controls. Tumor TLR9 protein expression was not associated with prognosis.

Conclusions

Tumor TLR9 expression is not associated with prognosis in AA TNBC. Significant differences were detected in TLR9 variant MAFs between EAs and AAs. They may affect TLR9 expression and function. Rs352140, which may protect from breast cancer, is 1.6 X more common among EAs. These findings call for a detailed analysis of the contribution of TLR9 to breast cancer pathophysiology and health disparities.

Reprint of: Microglial toll-like receptors and Alzheimer's disease

Microglial activation represents an important pathological hallmark of Alzheimer's disease (AD), and emerging data highlight the involvement of microglial toll-like receptors (TLRs) in the course of AD. TLRs have been observed to exert both beneficial and detrimental effects on AD-related pathologies, and transgenic animal models have provided direct and credible evidence for an association between TLRs and AD. Moreover, analyses of genetic polymorphisms have suggested interactions between genetic polymorphisms in TLRs and AD risk, further supporting the hypothesis that TLRs are involved in AD. In this review, we summarize the key evidence in this field. Future studies should focus on exploring the mechanisms underlying the potential roles of TLRs in AD.

Microglial toll-like receptors and Alzheimer's disease

Microglial activation represents an important pathological hallmark of Alzheimer's disease (AD), and emerging data highlight the involvement of microglial toll-like receptors (TLRs) in the course of AD. TLRs have been observed to exert both beneficial and detrimental effects on AD-related pathologies, and transgenic animal models have provided direct and credible evidence for an association between TLRs and AD. Moreover, analyses of genetic polymorphisms have suggested interactions between genetic polymorphisms in TLRs and AD risk, further supporting the hypothesis that TLRs are involved in AD. In this review, we summarize the key evidence in this field. Future studies should focus on exploring the mechanisms underlying the potential roles of TLRs in AD.